Torque teno virus (TTV), a species of Anellovirus, is a non-enveloped single stranded DNA virus with a wide range of animal hosts. The incidence of TTV is quite ubiquitous throughout the world. A total of 235 serum samples obtained from 137 pigs and 98 cattle at slaughterhouses in Korea during April 2005 to May 2005 were tested by TTV-specific PCR as to monitor prevalence of TTV among swine and cattle. As a result, the prevalent rates of TTVs in pigs and cattle were 43.1% and 4.1%, respectively. It seems that TTV infection is quite prevalent in swine population.

The present study was done to demonstrate ADV antigens in frozen and paraffin sections from ADV-infected pigs and cell cultures by using of the IGS method. Tissue specimens from 3 young pigs infected with ADV-phylaxia strain and of 2 healthy pigs were used. Fibroblastic cells originated from pig brain and BHK cells were grown and confluent monolayers were infected with the virus. Two monoclonal antibodies and a specific hyperimmune serum to ADV were used as the source of primary antibodies for both the IGS and immunoperoxidase methods. Application of the IGS method yielded a black fine granular reaction in positive areas, and the results were superior to those obtained using the immuno-peroxidase technique for all cases tested. The IGS method might be useful in the detection of various viral antigens in tissue sections

Four colostrum-deprived, 1 day old pigs were orally infected with the porcine enterovirus isolated in Korea. Two of the pigs were treated with dexamethasone (5mg/kg/day) for 3 days. The others as control were infected with porcine enterovirus only. The treated, infected pigs developed ataxia at 3 postinoculation days, neural disorders at 8 postinoculation days, 1 week earlier than those of the controls. Histopathological examination of both the treated and the control pigs revealed non-purulent polioencephalomyelitis consisting of neuronal degeneration, perivascular cuffing, meningeal infiltration, focal and diffuse gliosis. The severity of the histopathological lesions in the treated pigs was more prominent than those of the controls

The present study was carried out to determine viral antigens and its morphogenesis in the ultrathin frozen and araldite sections of cell cultures infected with ADV by protein A-gold labelling. ADV antigens were labelled with 10nm gold probes, and electron-dense gold particles were mainly present on viral nucleocapsids and viral envelopes. Immunogold labelling in the ultracryosections showed a very low degree of interaction with tissue structures. Immunogold labelling in the ultrathin cryosections can be useful tool for the detection of ADV antigens, and the technique also may provide its great potential for immunocytochemical studies on various virus-host cell interactions